Double side seamer

ABSTRACT

A double side seamer stitches a pair of mating carton blanks together to form a two-piece carton in a single pass. The seamer frame has a pass-through window provided with guides to support the folded carton blanks in side-by-side edge lapping relation for defining a top set of overlapping edges and a bottom set of overlapping edges. A separate stitcher head is provided for seaming each set of edges and a timer is connected to the stitcher heads to synchronize initiation of the stitcher heads after each stitch cycle and thereby enable both seams to be formed at the same time.

United States Patent lnventor DOUBLE SIDE SEAMER 9 Claims, 5 Drawing Figs.

Int. Cl.

Field of Search 227/2, 4.5,

References Cited UNITED STATES PATENTS Spiller Primary Examiner-Granville Y. Custer, Jr. Artorney-William P. Porcelli ABSTRACT: A double side seamer stitches a pair of mating carton blanks together to form a two-piece carton in a single pass. The seamer frame has a pass-through window provided with guides to support the folded carton blanks in side-by-side edge lapping relation for defining a top set of overlapping edges and a bottom set of overlapping edges. A separate stitcher head is provided for seaming each set of edges and a timer is connected to the stitcher heads to synchronize initiation of the stitcher heads after each stitch cycle and thereby enable both seams to be formed at the same time.

3 Sheets-Sheet l lNVfA/TO? Patented March 30, 1971 I 3,572,573

3 Sheets-Sheet 5 poems sms SEAMER BACKGROUND OF THE INVENTION It has been the practice in forming two-piece cartons to provide a machine with a single stitcher head such as is shown in Spiller et al. US. Pat. No. 2,398,053. A first body joint is formed between matching edges of a pair of carton blanks. Thereafter, a second joint is formed in a completely separate operation, resulting in exceptionally high manufacturing costs for the carton maker.

SUMMARY OF THE INVENTION In accordance with the present invention, a double side seamer machine is provided for simultaneously stitching both body joints between mating carton blanks to effect a complete side stitching operation during a single pass through themachine. The machine is equipped with two stitcher heads, one for each joint. Each stitcher head is operated from a continuously running motor and includes clutch and brake controls that stop the head after each stitch cycle is completed. A common actuator is connected to the cycle controls for each head to synchronize initiation of succeeding stitch cycles of each stitcher head and thereby allow the seaming of both body joints in a single pass.

The double side seamer provides a more uniform product and uses only about half the time formerly required. The actuator for synchronizing the action of the stitcher heads is in the form of a pulse timer which provides pulses at timed intervals sufficient to allow completion of a stitch cycle before the next pulse. After each stitch cycle, the operator advances the blanks in unison to prepare for the next set of stitches.

The stitching sequence of each head is controlled by a separate limit switch that senses the presence of the corresponding carton blank. Each limit switch remains closed until the corresponding carton seam moves completely past the stitcher heads.

Initial alignment of the blanks is facilitated by separate target stops that are provided for initially engaging and locating the leading edges of the blanks.

A foot switch starts the operation by releasing the target stops and activating the pulse timer.

Other features and advantages of the invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which show structure embodying preferred features of the present invention and the principles thereof, and what is now considered to be the best mode in which to apply these principles.

DESCRIPTION OF THE DRAWINGS In the accompanying drawings forming a part of the specification, and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a perspective view of the machine taken from the operator side thereof;

FIG. 2 is an enlarged fragmentary front view, partly in section and partly broken away, to show the guide and support structure for positioning a set of carton blanks in a doubleseam configuration;

FIG. 3 is an enlarged fragmentary section taken as indicated on line 3-3 of FIG. 2 and showing the target stop and clincher pad structures;

FIG. 4 is a schematic diagram of the electrical control circuit for the machine; and

FIG. 5 is a fragmentary perspective view of a clincher pad.

DESCRIPTION OF PREFERRED EMBODIMENT side frames 11 that carry a lower bridge structure 12 and an upper bridge structure 13. The cross bed and upper bridge 13 define a pass-through window region W where a mating pair of folded carton blanks l4 and 15 (see FIG. 2) are shown positioned in side by side relation to present top and bottom sets of oppositely directed overlapping edges or body joints. The machine of this invention is arranged to stitch both body joints simultaneously during a single pass through the window.

A bottom stitching head 16 is mounted on the lower bridge structure 12 and has a clincher pad 17 projecting into the window space to receive the edge of the short leg 148 of carton blank 14 and the edge of the long leg 15L of carton blank 15.

A top stitching head 18 is suspended from the upper bridge structure 13 and has a clincher pad 19 disposed within the window space to receive the edge of the long leg ML of carton blank 14 and the edge of the short leg of carton blank 15. The bottom stitching head may be moved to the right of the top stitching head to reverse the relative positions of the long leg and short leg of the carton blank. This is sometimes desirable in order to obtain tabs inside or outside the box as preferred and eliminates the need for opposite hand clincher pads.

Except for the clincher pads 17, 19 shown herein, each stitching head 16, 18 may be of the-type shown in Spiller et al. US. Pat. Pat, No. 2,398,053. The clincher pads l7, 19 are essentially identical. Clincher pad 19 is shown in FIG. Sto illustrate the manner in which the oppositely directed edges are positioned on opposite sides of an intermediate web 19W that carries the anvil 19A. The edges are guided into lapping contact by means of the guide shoe 198 to receive the staple that is driven through both edges while the'same are resting at the anvil region that is located to the rear of the web 19W.

The cross bed 10 is provided with left-hand and right-hand side gauge assemblies 20, 21 to receive and guide the folded corners of carton blanks l4, 15. A set of parallel intermediate support rails 22 equipped with antifriction wheels 22W are seated on the cross bed 10 to supplement the guiding and supporting of the carton blanks.

The upper bridge I3 is provided with left-hand and righthand live stop assemblies 23, 24 having depending targets 23T, 24T disposed to engage the leading edges of the carton blanks for facilitating initial alignment thereof in preparation for the stitching operation. Solenoids 238, 248 FIGS. 3 and 4) normally lock the targets in the positions illustrated and are energized through a foot switch 25 to release the targets and allow the operator to push the aligned carton blanks forwardly through the window.

A track 26 provided on the lower bridge 12 accommodates lateral adjustment of the lower stitcher head 16. A track 27 on the upper bridge 13 accommodates lateral adjustment of the top stitcher head 18 and of the live stop assemblies 23, 24. The live stop assemblies include lengthwise bars 23L, 24L shiftable laterally along the track 27 and vertical bars 23V, 24V carrying the targets and shiftable to and fro along the lengthwise bars.

The cross bed 10 has fore and aft rack-type tracks 28 to accommodate lateral adjustment of the side gauge assemblies 20, 21. The side gauge assemblies include carriages 20C, 21C supporting iron rails 20R, 21R. The left-hand side gauge rail 20R is shown provided with a limit switch 20L that is lengthwise adjustable therealong, to sense the presence of the carton blank 14. Similarly, the right-hand side gauge rail 21R is provided with a limitswitch 21L for sensing carton blank 15.

SUMMARY OF OPERATION The machine is initially adjusted to the size of the carton blanks that are to be run. The blank 15 is fed into the clincher pads 17 and 19 with its folded corner against the right-hand side gauge rail 21R until the leading edge abuts the target stop MT. The blank 14 is fed into the clincher pads 17 and 19 with its folded corner against the left-hand side gauge rail 20R until the leading edge abuts the target stop 2ST.

Assuming the body joints defined between the blanks l4, 15 are aligned, both limit switches 20L, 21L are engaged by the blanks at the leading edges thereof and are held closed. The operator steps on the foot pedal 25 while urging the aligned blanks forwardly against the target stops 23T, 24T. When the foot pedal switch 25 is energized, both target solenoids 238, 248 and both stitcher heads 16, 17 begin to operate. The target solenoids 238, 248 release the target stops 23T, 24T so that the blanks can be pushed through after the first set of stitches is applied. The spacing of the stitches is determined by the speed at which the blanks are advanced relative to the timing of the actuating pulses from a timer 34.

The stitcher heads continue to stitch so long as the foot switch 25 and the side gauge limit switches L, 21L are held actuated. Normally, the machine continues until the trailing edges of the blanks move off thelimit switches 20L, 21L. The operator then releases the foot switch, loads a second set of blanks and repeats the operation;

In the illustrated machine, a pair of seams are formed at the same time to simplify the loading and handling operations. The former mechanisms on the individual stitcher heads are maintained in general synchronism by the pulse timer and the associated circuitry but without mechanical interconnections between the heads.

The pulse timer 34 (FIGS. 1 and 4) produces pulses at spaced intervals to synchronize the initiation of each stitch cycle and thereby determine the stitching rate. A single cycle control cam on each stitcher terminates each stitch cycle. The desired general synchronism can be maintained in this fashion up to a stitching speed of about 180 stitches per minute.

Control Circuitry For simplicity the relay control circuit of FIG. 4 illustrates the relay contacts separately of the relay coils. In general, a three-phase supply line 29 is shown connected through a main disconnect 30 and through separate starters 31 to each of the normally continuously running stitcher motors 32. As described in Spiller et al. US Pat. No. 2,398,053 each stitcher head is deactivated after each stitch cycle by means of a cycle control mechanism that typically includes a cam controlled clutch and brake. Separate transformers 33 are shown for supplying suitable energizing voltage for each of the relay control circuits designated generally as 16C and 18C. Each control circuit incorporates a standard rectifier box B such as a Warner RF-400 unit which is not described in detail herein.

A number of the circuit elements appearing in the diagram are physically incorporated in the stitcher heads 16, 18. Thus, each of the stitcher head control circuits 16C, 18C are shown to include a stitcher cam limit switch 16L, 18L that opens on each full revolution of the stitcher cam, an adjustable brake control winding 16B, 188 a clutch-brake relay ICR having a normally closed contact lCR-l which opens to release the brake, a normally open contact lCR-Z which closes to energize the clutch windings 16W, 18W and a second normally open contact lCR-3 which closes to provide a hold circuit for the relay coil lCR.

The control circuit 16C for the stitcher head 16 that stitches the left-hand or bottom seam includes the left-hand side gauge limit switch 20L while the control circuit 18C includes the corresponding right-hand side gauge limit switch 21L.

The control circuits are interconnected to operate in synchronism by means of an actuating circuit that includes the foot switch 25, a pulse timer 34 and a sequencing relay 2CR. For control circuit 18C, the relay 2CR has a normally open contact 2CR1 in series with the side gauge limit switch 21L to be shunted by the hold contact lCR-3. Similarly for control circuit 16C, the relay 2CR has a normally open contact ZCR-Z in series with the side gauge limit switch 20L. The foot switch is also shown connected directly to each of the target solenoids 23S, 248.

The operator depresses the foot switch 25 to energize the pulse timer 34. The pulse timer 34 generates an on-off cycle of 110 volt current pulses to energize the sequencing relay coil 2CR.

The normally open contact 2CR-1 closes during the "on" part of the cycle to energize relay 1CR of control circuit 18C. Correspondingly, the normally open contact 2CR-2 closes to energize relay lCR of control circuit 16C.

For each stitcher and associated control circuit, the contacts lCR-l open to release the brake, the contacts lCR-2 close to activate the clutch windings 16W, 18W and contacts lCR-3 close to provide hold circuits for the relay coils 1CR. Each clutch engages each stitcher motor to its stitcher shaft to apply a stitch. The cam (not shown) on each stitcher shaft operates to open the corresponding stitcher cam limit switch 16L, 18L partway through the cycle to deenergizc the hold circuits of relays lCR. The on" cycle of the pulse timer is selected to terminate before the stitcher cams activate the stitcher cam limit switches. Thus, the contacts 1CR-1 and lCR-Z, respectively, reset to deenergize the clutch control 16W, 18W and to energize the brake control 16B, 188 so that each stitcher head completes one cycle and stops automati cally.

The next stitch cycle is initiated by the pulse timer 34 and the sequence continues until the side gauge limit switch or the foot switch is released. it will be noted that the formers of the stitching heads are maintained in general synchronism so that both are down about one-third of the total cycle to allow about two-thirds of the total cycle for the operator to move the blanks.

When the carton blanks are profiled so as to define different length body joints, the blanks are positioned with their aligned edges forward, so that stitching of both body joints starts at the same time. Assuming the left-hand or lower body joint is longer, the right side gauge limit switch 21L is set to run off the carton blank 15 before the left hand side gauge limit switch 20L runs off blank 14. From this point until the left limit switch 20L is cleared only the left-hand stitcher head 16 will operate.

Thus while preferred constructional features of the invention are embodied in the structure illustrated herein it is to be understood that changes and variations may be made by those skilled in the art.

lclaim:

l. A double side seamer for forming two-piece cartons in a single pass, said seamer having a pass-through region bordered by lengthwise guide structure for supporting a pair of mating folded carton blanks in side-by-side relation to present top and bottom sets of oppositely directed overlapping edges for movement through said region, a top stitcher means having a clincher means to support the top set of edges of said blanks and guide the same into lapping contact for forming a top joint seam line during movement of the blanks through said region, a bottom stitcher means having a clincher means to support the bottom set of edges of said blanks and guide the same into lapping contact for fonning a bottom joint seam line during movement of the blanks through said region, each of said stitcher means including cycle control means for deactivating the same after each stitch cycle, and means connected to each of said cycle control means to synchronize initiation of succeeding stitch cycles of said top and bottom stitcher means.

2. A double side seamer as claimed in claim 1 wherein said seamer has an upper bridge and a lower bridge flanking said pass-through region, said upper bridge having a track extending transversely of said region and supporting said top stitcher means in transversely adjustable relation and said lower bridge having a track extending transversely of said region and supporting said bottom stitcher means in transversely adjustable relation.

3. A double side seamer as claimed in claim 1 wherein said lengthwise guide structure includes a cross bed having a track extending transversely of said region, a pair of carriages supported on said cross bed for movement along said track, each carriage having a side gauge rail projecting through said region for supporting a corner region of the corresponding folded carton blank.

4. A double side seamer as claimed in claim 1 wherein said seamer has an upper bridge spanning said region and having a track extending transversely of said region and transversely adjustably supporting a sufficient number of target stop assemblies to align the blanks, each target stop assembly including a depending vertical rail, a lengthwise'rail adjustably supporting the vertical rail and a retractable stop supported by the vertical rail to assume a position for establishing initial alignment of the leading edges of the carton blanks.

5. A double side seamer as claimed in claim ll wherein each cycle control means includes acontrol circuit for deactivating the corresponding stitcher means after each stitch cycle and the means for synchronizing comprises a pulse timer connected for providing actuating pulses simultaneously to said control circuits at predetermined intervals large enough to enable completion of a stitch cycle between successive pulses.

6. A double side seamer as claimed in claim 5 wherein said seamer has a separate limit switch responsive to a corresponding carton blank for establishing a connection of the pulse timer to the corresponding control circuit during the time when such carton blank is positioned at the corresponding stitcher means.

7. A double side seameras claimed in claim 6 wherein said lengthwise guide structure includes across bed having a track extending transversely of said region, a pair of carriages supported on said cross bed for movement along said track, each carriage having a side gauge rail projecting through said region for supporting a corner region of the corresponding folded carton blank, each side gauge rail mounting one of said limit switches to respond to the comer region of the corresponding carton blank.

8. A double side seamer as claimed in claim 6 wherein said seamer has an upper bridge and a lower bridge flanking said pass-through region, said upper bridge having a track extending transversely of said region and supporting said top stitcher means in transversely adjustable relation and said lower bridge having a track extending transversely of said region and sup porting said bottom stitcher means in transversely adjustable relation.

9. A double side seamer as claimed in claim 6 wherein said seamer has an upper bridge spanning said region and having a track extending transversely of said region and transversely adjustably supporting a sufficient number of target stop assemblies to align the blanks, each target stop assembly including a depending vertical rail, a lengthwise rail adjustably sup porting the vertical rail and a retractable stop supported by the vertical rail to assume a position for establishing initial alignment of the leading edges of thecarton blanks. 

1. A double side seamer for forming two-piece cartons in a single pass, said seamer having a pass-through region bordered by lengthwise guide structure for supporting a pair of mating folded carton blanks in side-by-side relation to present top and bottom sets of oppositely directed overlapping edges for movement through said region, a top stitcher means having a clincher means to support the top set of edges of said blanks and guide the same into lapping contact for forming a top joint seam line during movement of the blanks through said region, a bottom stitcher means having a clincher means to support the bottom set of edges of said blanks and guide the same into lapping conTact for forming a bottom joint seam line during movement of the blanks through said region, each of said stitcher means including cycle control means for deactivating the same after each stitch cycle, and means connected to each of said cycle control means to synchronize initiation of succeeding stitch cycles of said top and bottom stitcher means.
 2. A double side seamer as claimed in claim 1 wherein said seamer has an upper bridge and a lower bridge flanking said pass-through region, said upper bridge having a track extending transversely of said region and supporting said top stitcher means in transversely adjustable relation and said lower bridge having a track extending transversely of said region and supporting said bottom stitcher means in transversely adjustable relation.
 3. A double side seamer as claimed in claim 1 wherein said lengthwise guide structure includes a cross bed having a track extending transversely of said region, a pair of carriages supported on said cross bed for movement along said track, each carriage having a side gauge rail projecting through said region for supporting a corner region of the corresponding folded carton blank.
 4. A double side seamer as claimed in claim 1 wherein said seamer has an upper bridge spanning said region and having a track extending transversely of said region and transversely adjustably supporting a sufficient number of target stop assemblies to align the blanks, each target stop assembly including a depending vertical rail, a lengthwise rail adjustably supporting the vertical rail and a retractable stop supported by the vertical rail to assume a position for establishing initial alignment of the leading edges of the carton blanks.
 5. A double side seamer as claimed in claim 1 wherein each cycle control means includes a control circuit for deactivating the corresponding stitcher means after each stitch cycle and the means for synchronizing comprises a pulse timer connected for providing actuating pulses simultaneously to said control circuits at predetermined intervals large enough to enable completion of a stitch cycle between successive pulses.
 6. A double side seamer as claimed in claim 5 wherein said seamer has a separate limit switch responsive to a corresponding carton blank for establishing a connection of the pulse timer to the corresponding control circuit during the time when such carton blank is positioned at the corresponding stitcher means.
 7. A double side seamer as claimed in claim 6 wherein said lengthwise guide structure includes a cross bed having a track extending transversely of said region, a pair of carriages supported on said cross bed for movement along said track, each carriage having a side gauge rail projecting through said region for supporting a corner region of the corresponding folded carton blank, each side gauge rail mounting one of said limit switches to respond to the corner region of the corresponding carton blank.
 8. A double side seamer as claimed in claim 6 wherein said seamer has an upper bridge and a lower bridge flanking said pass-through region, said upper bridge having a track extending transversely of said region and supporting said top stitcher means in transversely adjustable relation and said lower bridge having a track extending transversely of said region and supporting said bottom stitcher means in transversely adjustable relation.
 9. A double side seamer as claimed in claim 6 wherein said seamer has an upper bridge spanning said region and having a track extending transversely of said region and transversely adjustably supporting a sufficient number of target stop assemblies to align the blanks, each target stop assembly including a depending vertical rail, a lengthwise rail adjustably supporting the vertical rail and a retractable stop supported by the vertical rail to assume a position for establishing initial alignment of the leading edges of the carton blanks. 